Ferrari Maud C O, Crane Adam L, Brown Grant E, Chivers Douglas P
Department of Biomedical Science, WCVM, University of Saskatchewan, SK, Canada.
Department of Biology, University of Saskatchewan, SK, Canada.
Sci Rep. 2015 Feb 6;5:8309. doi: 10.1038/srep08309.
Factors predicting the outcome of predator invasions on native prey communities are critical to our understanding of invasion ecology. Here, we tested whether background level of risk affected the survival of prey to novel predators, both native and invasive, predicting that high-risk environments would better prepare prey for invasions. We used naïve woodfrog as our prey and exposed them to a high or low risk regime either as embryos (prenatal exposure) or as larvae (recent exposure). Tadpoles were then tested for their survival in the presence of 4 novel predators: two dytiscid beetles, crayfish and trout. Survival was affected by both risk level and predator type. High risk was beneficial to prey exposed to the dytiscids larvae (ambush predators), but detrimental to prey exposed to crayfish or trout (pursuit predators). No effect of ontogeny of risk was found. We further documented that high-risk tadpoles were overall more active than their low-risk counterparts, explaining the patterns found with survival. Our results provide insights into the relationship between risk and resilience to predator invasions.
预测捕食者入侵对本地猎物群落影响结果的因素，对于我们理解入侵生态学至关重要。在此，我们测试了背景风险水平是否会影响猎物对本地和入侵新捕食者的生存能力，预计高风险环境会让猎物为入侵做好更好准备。我们使用未接触过捕食者的林蛙作为猎物，并在其胚胎期（产前暴露）或幼体期（近期暴露）将它们置于高风险或低风险环境中。然后测试蝌蚪在面对4种新捕食者时的生存情况：两种龙虱科甲虫、小龙虾和鳟鱼。生存情况受到风险水平和捕食者类型的影响。高风险对暴露于龙虱幼虫（伏击型捕食者）的猎物有益，但对暴露于小龙虾或鳟鱼（追捕型捕食者）的猎物有害。未发现风险个体发育的影响。我们进一步记录到，高风险蝌蚪总体上比低风险蝌蚪更活跃，这解释了生存方面的发现模式。我们的结果为风险与对捕食者入侵的恢复力之间的关系提供了见解。
